Stringed musical instrument



April 20, 1943. J.. w. M BRIDE STRINGED MUSICAL INSTRUMENT loo; 1: I 1

3 Sheets-Sheet 1 A .fl'vupmii.

Filed April 14, 1941 April 20, 1943. w, McBRlDE 2,316,799

STRINGED MUSICAL INSTRUMENT Filed April 14. 1941 3 Sheets-Sheet 2 \NVENTOR AMY April 20, 1943. J. w. M BRIDE STRINGED MUSICAL INSTRUMENT Filed April 14,- 1941 s Sheets-Sheet 5 gig. 12 43 5 \NVENTOR Jab W I376 firbe j/nu. ATTORNEY Patented Apr. 20, 1943 UNITED STATES PATENT OFFICE STRIN GED DIUSICAL INSTRUlVIENT John W. McBride, Burbank, Calif. Application April 14, 1941, Serial No. 388,379 Claims. (Cl. 84315) This invention relates to a stringed musical instrument, and more particularly to an instrument in which the pitch of the musical sound caused by vibration of any of the strings is capable of being determined by determining the free length of vibration of the string. This process is accomplished usually by stopping the string against a surface by the finger of the player.

This kind of stopping is commonly employed in playing such instruments as a guitar or violin, in which the neck of the instrument forms a convenient surface against which the string being played can be pressed by the finger.

In view of the fact that the fingers may be required to be placed over the strings at any point along the strings, proficiency in playing such an instrument is dependent upon manual and digital dexterity.

It is one of the objects of this invention to make it possible to control or adjust the free length of the vibrating string in a more convenient manner, and without the necessity of materially shifting the position of the hand.

In playing guitars, it is sometimes required to pass the finger in a continuous manner longitudinally along at least a portion of the vibrating string, and thereby continuously alter the free length of the string. It is another object of this invention to make it possible to vary the free length in a simpler and easier manner.

In order to accomplish these results, use is made of an elongated rod arranged beneath the string to be controlled, and extending generally in the direction of the string. The rod has a ridge having a crest that progresses angularly about the longitudinal axis of the rod, in a helical-like manner. By adjustment of the rod about a longitudinal aXis, the string is caused to rest upon any desired point of the crest, and its free length of vibration is thus determined. The rotation of this rod to cause the crests to assume the desired positions is accomplished by depressing finger keys. Accordingly, it is another object of this invention to provide a mechanism under the control of the fingers of the player, for rotation of a string stopping bar or rod of this character.

The invention possesses many other advantages, and has other objects which may be made more easily apparent from a consideration of one embodiment of the invention. For this purpose there is shown a form in the drawings accompanying and forming part of the present specification. This form will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of this invention is best defined by the appended claims.

Referringto the drawings:

Figure 1 is a plan view of a musical instrument incorporating the invention;

Fig. 2 is an enlarged part sectional view, taken along plane 22 of Fig. 1, a part of the instrument being omitted to reduce the size of the figure;

Fig. 3 is a sectional view taken along 3-3 of Fig. 1;

Fig. 4 is a sectional view 4-4 of Fig. 2;

Fig. 5 is an enlarged sectional view taken along plane 5-5 of Fig. 2, some of the parts being broken away;

Fig. 6 is a sectional view taken along 6-6 of Fig. 5;

Fig. 7 is a fragmentary sectional view along plane 1-4 of Fig. 6;

Fig. 8 is a sectional view taken along plane 88 of Fig. 2, some of the parts being omitted;

Fig. 9 is a pictorial view of a finger button adapted to be used in the instrument incorporating the invention;

Fig. 10 is a pictorial view of one of the elements utilized in connection with the finger buttons;

Fig. 11 is a pictorial view of one of the rotatable rods for determining the free length of the vibrating string; and

Fig. 12 is an enlarged sectional view illustrating the manner in which the rotatable rod cooperates with the tensioned string.

In the present instance, the invention is shown as incorporated in a guitar, although it is capable of being utilized with many types of stringed musical instruments. Instead of utilizing a hollow resonant body, to set up or augment the sound vibrations, the instrument is shown as capable of being connected with appropriate electrical amplifying apparatus. For this purpose the body I (Figs. 1 and 2) of the guitar is shown as made of solid wood or other appropriate material. Extending from the body I is the elongated neck portion 2. This neck portion terminates in the flat peg board 3. In the present instance, a four string guitar is illustrated, the four strings being designated respectively by the reference characters 4, 5, 6 and I.

For maintaining these strings under tension, a bridge member 8 (Fig. 2) may be appropriately plane taken along plane plane taken supported adjacent the end of the body portion I. This bridge is located in the recess 3| formed in the top of body I. This bridge member 8 is provided with a series of apertures 9, and each aperture may be provided with a rearwardly extending enlarged portion I0. These apertures 9 serve as anchoring apertures for the strings. Each of the strings for example may be provided with an enlarged ball end II. The strings may be passed through the respective apertures 9, the ball II being accommodated in the enlarged portion Iii. The ball being larger than the aperture 9, it engages the edge of the aperture 9, and tension on the strings may be exerted.

The board 3 may be provided with the posts or pegs I2, I3, I4 and I5, serving as anchors for the free ends of the strings. These posts may be arranged to be rotated as desired by the thumb pieces IE, to wind the strings upon the posts.

The strings are stretched under tension so that they are in contact with two separated points. The pitch of the note caused by free vibration between these points is a function of the mass per unit length of the string, and the tension. Shortening of the free vibrating length of the string causes an increase in pitch. All this is well understood. The bridge 8 has an upper surface upon which the right hand ends of the strings rest. Therefore the edge of this bridge 8 forms one of the stationary points.

The peg board 3 forms an abrupt shoulder I9 (Fig. 6) with the neck 2. At this portion of the neck 2, there is a metal bracket II having a vertical wall I8 which is disposed against the shoulder I3. This bracket I1 is appropriately fastened to the top surface of the neck 2. The vertical wall I8 is provided at its upper edge with a series of slots 20 (Figs. 4 and 6). The strings slope downwardly along board 3. They contact the bottom surfaces of these slots. As will be described hereinafter, the free or open position of the strings is determined not by the slots 23, but by a devicehereinafter to be described, and operating to form stops for the strings near the right hand edge of bracket I'I. As in the usual guitar, the neck member 2 may be provided with a plate 2I carrying the graduated marks 2I', and underlying the strings 4, 5, 6 and 1. Its left hand edge as shown most clearly in Figs. 3, and 6, may abut the right hand edge of the bracket I'I.

As most clearly illustrated in Fig. 2, the bridge 8 may be concealed beneath a sheet metal cover member 22. This cover member 22 is shown as having 2. depending wall 23 extending downward over the edge of the body I. Conveniently this right hand edge of the body I may be provided with a recess so as to permit the depending member 23 to lie flush with the body I. This cover member 22 may be secured as by the aid of the screws 24.

At its front edge the cover member 22 may be provided with a stepped portion 25 connected as by the sloping connection 26 with the main part of the cover member. This portion 25 is disposed so as to be flush with the top surface of body I. Through connection 26 there are clearance apertures 21 to permit free passage of the strings. An anchor for this end of the cover piece22 may be provided by the aid of a strap 28 fastened Y25 and having a slot 29 therein. This slotted end is intended to be passed underneath the head of a screw 33 located in the bottom of the cutoutspace3I. i V V to the lower side of extension The vibrations of the strings 4, 5, 5 and I are intended to affect an electro-magnetic pickup device indicated diagrammatically by the reference character 32. The strings are shown in this instance as passing directly above the pickup device 32. Leads from this device may extend through aperture IIlI (Fig. 1) to the exterior of the instrument.

In the conventional playing of a guitar, the fingers of the left hand are used to stop the strings 4, 5, 8 and I against the neck. In accordance with the present invention, the fingers are utilized to depress the closely spaced finger buttons 33, 34, 35 and 35 (Figs. 1, 5 and 9), located near the end of the neck. The hand does not have to be moved from the end position, and accordingly extreme manual dexterity i no longer essential.

The manner in which these buttons control the free length of the strings will now be described in connection with string 5. The mechanisms for the other strings are quite similar and will be described only insofar as they may differ in detail from the mechanism associated with string 5.

Located beneath the string 5 is a rotatable rod 31 (Figs. 2, 5, 6, 8, 11 and 12). Its axis of rotation is substantialy parallel to the string. At its right hand end this rod is provided with a stub shaft portion 38 journaled in a bracket 39 (Fig. 2). This bracket 39 overlies the vertical wall 40 formed in the body member I and located at the right hand end of the hollowedout portion 4| of the body I. The left hand portion of rod 31 carries the extension 42 (Figs. 6

and 11) that is journaled in the vertical wall I8 of the bracket II. This rod 31, asshown most clearly in Figs. 11 and 12, is provided with a helical-like ridge 43. This ridge 43 progresses angularly along the longitudinal axis of the rod 31. This ridge furthermore is high enough so that it contacts the lower. side of the string 5 when the rod 31 is turned sufficiently from the beginning position of Fig. 8. Furthermore, as the rod 31 is rotated in a clockwise direction as viewed in Fig. 8, the ridge 43 is first caused to contact the lower side of the string 5 at the end of the string nearest the wall I8, continued rotation causes the point of contact to move toward the bridge end of the nistrument. There is a correspondng shortening of the free length of the vibrating string. In the present instance, the ridge 43 has a sharply deviating end II2 (Figs. 5 and 11), which-ensures that the string 5 will be always in contact with the ridge, even for the extreme or open position of Fig. 8.

The finger key 35 is associated with the rod 31 so that pressure exerted on this key inwardly, as by one of the fingers of the left hand of the player, will cause the rod to be rotated. The extent of the depression of the key in the direction transverse to the neck 2 determines the angular position of the rod 31, and the corresponding position of the point along the ridge 43 which is in contact with string 5.

Key 35 is shown to best advantage in Figs. 5, 6 and 9. It is guided for movement transverse of the instrument in a manner now to be described. Thus the key 35 has a lower portion 44. The lower surface of this portion 44 rests upon the bottom of a square-cut slot 45 in the bracket II. This slot 45 is undercut at the left hand edge, there being an overhanging flange 46 as shown most clearly in Fig. 6. The lower portion 44 is provided with the projecting side flanges 41 and 48. The left hand flange 48 is accommodated beneath the projecting edge 46. The right hand flange 47 is overlaid by a detachable stop piece 49. This piece is shown to best advantage in Fig. 10. It is screwed to the bottom of the bracket I! as by the aid of screws accommodated in the apertures 50.

By this means the key 35 is guided for transverse movement. A rack I arranged on portion 44. This rack is adapted to engage the pinion 52 mounted on the rod 31.

As shown most clearly in Figs. 5 and 6, this pin ion 52 is attached to the reduced portion 42 of the rod 3'! and abut-s a shoulder formed between this reduced portion 42 and an enlarged portion 53. The rod 31 is constantly urged and in a resilient manner in a counterclockwise direction by the aid of a helical spring 54 disposed over the extension 42. The right hand end of this spring is anchored in a collar 55 that abuts the pinion 52. It is provided with a set screw 55 whereby the angular position of the collar 55 may be adjusted. At the left hand end of the extension 42 there is a collar 51 which is free to rotate on the extension 42 and to which is anchored the left hand end of the spring 54. This collar is arranged to be angularly adjustable within the sleeve 58 shown as formed integral with the wall ill of bracket IT. The collar 51 may be maintained in adjusted position as by the aid of the set screw 59.

Thus in order to adjust the tension of the spring 54, either one or both of the collars 55 or 51 may be appropriately rotated and maintained in adjusted position.

The constant force urging the shaft 42 and rod 31 in a counterclockwise direction causes the key 35 to be urged upwardly as viewed in Fig. 5. A stop is provided to limit this upward movement at the point where the rod 3! assumes the position of Fig. 8. For this purpose the plate 49 (Fig. is utilized. This plate 43 has the projecting edges 60 and (H. The projecting edge 60 is arranged to overlie the flange 4'1. As shown most clearly in Fig. 9, the flange 41 is cut back at the finger engaging end of the button to accommodate the extension 60. In this way a shoulder 62 is formed on the button 35 which is urged against the extension 60 when the button 35 is released.

The other buttons 33, 34 and 36 similarly control the positions of bars 63, 64 and 65. The axes of all of the bars are parallel; and all of the buttons 33, 34, 35' and 36 are placed compactly adjacent the end of the neck portion 2. In this way the fingers of the left hand may be readily utilized without movement of the hand as awhole along the neck of the instrument.

Thus for example the rod 65 controlling the free length of string 4 carries the pinion 63 (Figs. 5 and 6). This pinion 66 is displaced in an axial direction from the pinion 52', but in other respects the mechanism is entirely similar to that already described. The extension BI of stop plate 49 operates against the corresponding abut ment on the lower portion of key 36. The torsion spring I02 in this case is somewhat longer than the spring 54.

Similarly the button 34 operates the rod 64. In this case the pinion 81 is spaced toward the left of the pinion 52. Accordingly, torsion spring I03 is somewhat shorter than spring 54.

The button 33 controlling the position of the rod 63 serves to rotate the pinion 68. In this case the pinion 68, as shown most clearly in Figs. 3 and 5, is arranged adjacent the left hand extremity of the reduced extension 59. An intermediate bearing standard H1 is provided for this extension 69. Within the bearing standard is the angularly adjustable collar II. The tension spring I2 has its left hand end anchored to the 'collar II. Its right hand end is anchored to the angularly adjustable collar 13 placed at the right hand end of the extension 69. Furthermore, in order to provide stops against upward movement of the keys 33 and 34 as viewed in Fig. 5, stop member 74 (of the same structure as stop 49) is utilized.

The rack and pinion mechanisms are provided with a cover member I5 (Figs. 1, 2, 3, 6 and 8). This cover member as shown most clearly in Figs. 4 and 6, has a notched flange 16 overlying the top edge of wall I8. At the opposite edge it has a flange 11 disposed slightly to the left of the left hand edges of the bars 31, 53,- and 65. Furthermore, the cover 15 has an end wall I8 (Fig. 5) having depending flanges I9 and 85, which are continuations respectively of the flanges I6 and I1. These flanges I9 and serve to support the cover I5 in a pivotal manner. Thus the flange I9 (Fig. 5) carries the pin shaft 8| engaging in an apertured ear 82 formed as an extension of the wall I8. The opposite flange 80 is arranged to overlie the threaded ear 83. This threaded ear is engaged by the screw 84 that serves as a pivot shaft for flange 80. The cover 15 may thus be swung up on these supports, to expose the finger button mechanism and to permit adjustments to be made.

As shown most clearly in Figs. 4 and 9, the top portion 85 of each of the finger keys or buttons 33, 34, 35 and 36 is arranged to telescope underneath the cover 75. This top portion may be provided with a series of marks 85 to serve as a guide for the player in determining how far the buttons must be pressed inwardly to secure a definite pitch. These marks are adapted to cooperate with the open edge 81 (Fig. 4) at the right hand side of the cover I5. The cover 75 may also be provided with spring fingers 88 located between the finger keys 33, 34, 35, 36, and adapted to snap over corresponding spring finger extensions 89 forked integrally with the bracket I1. These spring fingers serve detachably to restrain movement of cover 75 about the axis of pin BI and screw 84.

Control of the volume of the impulses transmitted through the pickup mechanism 32 is conveniently accomplished by the aid of a variable resistance embodied in the neck 2 of the instrument. Ihus leads 90 (Figs. 2, '7 and 8) extend from device 32 through an elongated aperture 90' in the instrument which leads to the chamber 92. One of these leads connects to a resistance 9I (Figs. 3, 4 and '7) located in the bottom of chamber 92. Sweeping over this resistance 9| is the contact arm 93. This arm is shown as integral with another arm I54 that contacts with a connection plate IIJBconnected to the other lead 93. The manner in which arms 53 and I54 are caused to move over resistance 9| and plate I05 may now be described.

Contact arms 93 and I84 are shown as attached to an arm 95, but insulated therefrom; arm is pivotally supported on a post 94 (Figs. 3, 4, 6 and 7). This arm 95 has a hub I65 that Provides asuitable journal support for the arm. This hub is restrained against axial movement by the aid of a screw I08 threaded radially into the hub and having a portion extending into a groove formed in the rod 94 (Fig. 6). Post 94 extends downwardly from the lower side of the bracket I! and is attached thereto. An aperture III (Fig. 6) extends from the recess 92 through neck 2, for accommodating this post. A helical spring 96 may be wound around the post urging the arm 95 in a counterclockwise direction. Thus one end of the spring 96 may be anchored to a pin 91 fastened to the arm 95. The inner end of the spring 96 is attached to the post 94;

The position of the contact arm 93 maybe adjusted by the aid of the extension 98. This extension carries a thumb button III'I projecting so as to lie alongside of the key 36. In the event that the instrument is supported on the lap of the player and the left hand of the player extends over the neck 2, the thumb may be used for the control of the position of the arm 95. As shown most clearly in Fig. 7, the rotation of arm 95 may be limited by the Wall I08 of the recess 92, serving as an abutment for the extension 98.

In the event that the left hand extends beneath the neck of the instrument, the post of the arm 95 may be controlled by the aid of the lever 99, located beneath neck 2. This lever 99 as shown most clearly in Figs. 4, 6 and '7, is fastened as by screw I99 to the lower end of hub I06. For this purpose this end of the hub is provided with internal threads. The radial extension IIII of the lever 99 engages in an appropriate slot in the hub I96 for restraining relative angular movement of the lever 99 .with respect to the hub.

The guitar, as suggested hereinabove, may be supported as by the aid of a sling hung around the neck. In this event the sling may be anchored to a button I90 arranged at the end of the body I. Alternatively, it may be supported in the lap of the player.

What is claimed is:

1. In a stringed musical instrument, means for tensioning a string between two fixed points, and means for adjusting the free length of the string, comprising a rotatable rod having a helical-like crest for engaging the string.

2. In a stringed musical instrument, means for tensioning a string between two fixed points, and means for adjusting the free length of the string, comprising a rotatable rod having a helical-like crest for engaging the string, and a finger button mechanism for operating said rod.

3. In a stringed musical instrument having one or more strings tensioned between two fixed points, a rod-like rotatable member having an axis of rotation substantially parallel to the string, and capable upon rotation to provide a stop that determines the free length of the string by contact therewith along any point of the string between limits, the free length of the string being dependent upon the angular position of the rod-like rotatable member.

4. In a stringed musical instrument, means for tensioning a string between two fixed points, and means for adjusting the free length of the string, comprising a rotatable rod having a helical-like crest adapted to engage the string, said rod being disposed beneath the string, a depressible button extending transversely to the string, and means forming an operative connection between the button and the rod for rotating said rod.

5. In a stringed musical instrument, means for tensioning a string between two fixed points, and

means for adjusting the free length of the string, comprising a rotatable rod having a helical-like crest for engaging the string, a pinion mounted on the rod, and a rack for operating the pinion and thereby to rotate said rod.

6. In a stringed musical instrument, means for tensioning a string between two fixed points, and means for constantly adjusting the free length of the string, comprising a rotatable rod having a helical-like crest for engaging the string, a pinion mounted on the rod, a rack for operating the pinion, and a helical spring disposed around the rod for urging said rod angularly to a position such as to maintain the crest out of operative relation with the string.

7. In a stringed musical instrument, having a neck portion and a body portion as well as one or more tensioned strings extending along the neck portion, one or more finger key mechanisms respectively for said strings and adjacent the end of the neck portion for determining the free length of the corresponding string, means for translating the string vibrations into electrical impulses, and a control member for adjusting the intensity of the impulses, said control member having two manually operable operating means extending on opposite sides of the neck for optional digital operation from either side of the neck.

8. In a stringed musical instrument, having a neck portion and a body portion as well as one or more tensioned strings extending along the neck portion, one or more finger keys adjacent the end of the neck portion, rotatable rods respectively extending beneath the strings for contacting the string and thereby determining the free length of the corresponding vibrating string, said rods having axes extending substantially parallel with the strings, and means for mechanically operating said rods in accordance with the operation of said keys, the free lengths being determined by the angular positions of the rotatable rods.

9. In a stringed musical instrument,'having a neck portion and a body portion as well as one or more tensioned strings extending along the neck portion, and one or more finger key mechanisms respectively for said strings and adjacent the end of the neck portion for determining the free length of the corresponding string, eachof said mechanisms including a key having an extension with a series of graduated marks, adapted to cooperate with a stationary index carried by the neck. I

10. In a stringed musical instrument having a neck portion and a body portion as well as one or more tensioned strings extending along the neck portion, one or more finger key mechanisms respectively for determining the free length of the corresponding string, and supported adjacent the end of the neck portion upon the instrument, means for translating the string vibrations into electrical impulses, and a variable resistance structure for adjusting the intensity of the impulses, comprising a rotatable member having an axis transverse to the strings, and adjacent the key mechanisms, and arms attached to the rotatable member and capable of digital control,

said arms extending on opposite sides of the neck I so as to make it possible to operate said variable resistance structure from either side or the instrument.

JOHN W. MCBRIDE. 

